Cluster Physics with Dark Energy
Abstract
Dark energy affects the abundance and evolution of clusters owing to their dependence on the geometry of the Universe and the power spectrum. Usually, there exits the degeneracy between σ_{8} and the matter energy density contrast {Ω _{{} m}^{0}}. We avoid this by using the explicit dark energy dependent rms linear mass fluctuation σ_{8} which is consistent with the CMB normalization for general constant dark energy equation of state, ω_{Q}. When we use the correct value of the critical density threshold δ_{c} = 1.58 into the cluster number density n calculation in the PressSchechter (PS) formalism, PS formalism predicts the cluster number consistent with both simulation and observed data at the high mass region. The improved coefficients of ShethTormen (ST) formalism by using the correct δ_{c} is also obtained. We found that changing ω_{Q} by ∆ω_{Q} = 0.1 from ω_{Q} = 1.0 causes the changing of the comoving numbers of high mass clusters of M = 10^{16}h^{1}M_{☉} by about 20 and 40% at z = 0 and 1, respectively.
 Publication:

International Journal of Modern Physics D
 Pub Date:
 2011
 DOI:
 10.1142/S0218271811019505
 Bibcode:
 2011IJMPD..20.1327L
 Keywords:

 Dark energy;
 clusters;
 spherical collapse model;
 mass function